<!doctype html>
<meta charset="utf-8">
<title>overscroll-behavior in root works</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-actions.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="/css/css-scroll-snap/support/common.js"></script>
<link rel="help" href="https://drafts.csswg.org/css-overscroll-behavior">
<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=954423">

<div style="height: 200vh"></div>

<iframe srcdoc="<style>:root { overscroll-behavior-y: contain }</style><div style='height: 200vh'></div>"></iframe>

<script>
promise_test(async function() {
  await new Promise(r => window.addEventListener("load", r, { once: true }));

  const iframe = document.querySelector("iframe");
  iframe.scrollIntoView();

  const bounds = iframe.getBoundingClientRect();

  const originalScrollPos = window.scrollY;

  assert_equals(typeof originalScrollPos, "number", "Scroll position should be a number");
  assert_not_equals(originalScrollPos, 0, "Should have scrolled to get the iframe into view");

  await new test_driver.Actions()
    .scroll(bounds.left + bounds.width / 2, bounds.top + bounds.height / 2, 0, -100)
    .send();

  assert_equals(window.scrollY, originalScrollPos, "overscroll-behavior should work on the root");
});
</script>
